Preparation and use of cyclododecatriene trialdehyde and related compounds

ABSTRACT

Disclosed herein are compositions and methods related to the hydroformylation of cyclododecatriene to form cyclododecatriene trialdehyde, and the conversion of the trialdehyde to the polyphenols of Formula 1: 
     
       
         
         
             
             
         
       
     
     where R, m p and Q are as defined herein. Curable compositions comprising compounds of Formula 1, including powder coating compositions, and methods of curing the compositions are also disclosed.

FIELD OF THE INVENTION

Disclosed herein is a method of hydroformylating cyclododecatriene(CDDT) in the presence of a rhodium catalyst to predominantly form thetriformylated cyclododecane, and the subsequent manipulation of theresulting aldehyde groups.

BACKGROUND OF THE INVENTION

Phenolic resins are synthetic materials that vary greatly in molecularstructure. This variety allows for a multitude of applications for theseresins; for example, use as a curing agent and/or to prepare thecorresponding epoxy, cyanate and/or allyl thermosettable resins. Thesecuring agents and/or resins can provide enhanced physical and/ormechanical properties to a cured composition, such as increased glasstransition temperature (Tg). To achieve improved properties, however,would require the resin to have a high level of functionality (i.e.,chemical groups available for cross linking). As the level offunctionality increases in these resins, so does their molecular weight.As the molecular weight increases, so does the melt viscosity of theresin, which can lead to difficulties in using such resins. Thus, workhas been conducted on the preparation of the aldehydes of CDDT, whichcan be further manipulated to create new monomers, oligomers and/orpolymers.

Hydroformylated CDDT has been a synthetic target for years because it isenvisioned as useful in the preparation of polymers. However,hydroformylation of CDDT results in a mixture of mono, bis, andtriformylated product, typically with the mono or bis formylated productdominating the product mixture. The triformylated product may beprepared, but in very poor yields. It is also very difficult to separatethe mono, bis, and trialdehydes.

U.S. Pat. No. 3,089,904 used a cobalt catalyst to hydroformylate CDDTand while the desired products were the mono and bis formylatedcompounds, the triformylated compound may also have been prepared,possibly as a minor component.

U.S. Pat. No. 3,184,432 described the hydroformylation of CDDT usingcobalt based catalysts and the conversion of the resulting mono, bis, ortrialdehydes to the corresponding mono, bis, or trialcohols. Thetrialcohol was not isolated.

U.S. Pat. No. 3,312,742 disclosed the hydroformylation of CDDT usingpalladium or cobalt based compounds in conjunction with Adkins catalystand the isolation of the resulting mono alcohol or mono formylatedproducts.

U.S. Pat. No. 4,251,462 taught the hydroformylation of CDDT using acombination of a rhodium catalyst and a dicobalt catalyst to generatemono, bis and trialdehydes. Example 3 in this patent reported thepreparation of a hydroformylated mixture comprising 13% bis aldehyde and85% trialdehyde (as measured by gas chromatography; the aldehydes do notappear to have been separated), where the reaction was run at 160° C.and >4000 psig using 500 ppm rhodium catalyst. The aldehydes of thispatent were then converted to the amines by reductive amination.

U.S. Pat. No. 5,138,101 disclosed an extraction method that enabled theseparation of product of a rhodium catalyzed hydroformylation of CDDTfrom the rhodium containing reaction mixture. Two differenthydroformylation reactions were run. In both reactions (see referenceexamples 2 and 15), mono, bis and triformylated products were formed,and in both reactions, the bis formylated compound was the majorproduct, followed by the mono formylated compound, and then thetriformylated product (amounts were based on GLC analysis of thereaction mixture.) Both reactions were also run at 125° C. andapproximately 260 psi. After cooling, the reaction mixture was thenextracted with an alcohol and water extraction mixture thatpreferentially extracts the products of the hydroformylation reactionfrom the rhodium containing reaction mixture.

U.S. Pat. No. 6,252,121 used phase separation to selectively separatethe cyclic hydroformylation product from the reaction mixture and thendistilled the product. Neither the hydroformylation of CDDT nor thepurification of the resulting products was described.

U.S. Pat. No. 7,683,219 conducted a hydroformylation reaction in thepresence of an aldehyde, which facilitated the phase separation of thehydroformylation product from the reaction mixture. Neither thehydroformylation of CDDT nor the purification of the resulting productswas described.

Current methods of hydroformylating CDDT preferentially form the monoand bis aldehydes; the trialdehyde, if formed, is a minor product. Theresulting products must then be separated, which is not a simple task.Or, higher yields of the trialdehyde may be formed, but under veryforcing conditions using high temperature and pressure.

It would be beneficial to be able to prepare the trialdehyde of CDDT inhigh yield using mild conditions. This would minimize the need to purifythe resulting product mixture, and facilitate the preparation ofderivatives thereof for use in the preparation of monomers, oligomers,and polymers.

SUMMARY OF THE INVENTION

The inventors have surprisingly and unexpectedly invented ahydroformylation method for the selective preparation of the trialdehydeof cyclododecatriene that does not require a separate step to remove themono and di aldehydes of cyclododecatriene.

In a first aspect, disclosed herein is a method of hydroformylatingcyclododecatriene to form the trialdehyde, the method comprising:

-   a) preparing a first mixture comprising a rhodium compound and an    organophosphite ligand in a solvent;-   b) heating the first mixture in the presence of a gas comprising CO    and H₂ to form a second mixture comprising an activated catalyst    complex; and-   c) combining cyclododecatriene and the second mixture to form a    third mixture.

In a second aspect, disclosed herein are compounds of Formula 1:

and methods of making such compounds, which are made by subjecting thecyclododecane trialdehyde to conditions sufficient to add twohydroxyaromatic groups per aldehyde or ketone.

In Formula 1, each m independently has a value of zero to 3, p has avalue of zero to 20, preferably zero to 5, most preferably zero to 1;each R is independently halogen, preferably fluorine, chlorine orbromine; nitrile; nitro; C₁-C₆ alkyl or C₁-C₆ alkoxy preferably thealkyl and alkoxy groups independently have 1 to 4, most preferably 1 to2 carbon atoms which may be substituted with one or more halogen atoms,preferably chlorine or bromine; or C₂-C₆ alkenyl or C₂-C₆ alkenyloxy,preferably the aforementioned alkenyl groups have 2 to 4, mostpreferably 2 to 3 carbon atoms; and each Q is independently hydrogen orC₁-C₆ alkyl, preferably the alkyl group has 1 to 4, most preferably 1 to2 carbon atoms. Each R group may independently be a C₃-C₄ alkylene groupthat optionally contains one or two double bonds and is bonded to twoadjacent carbons on the ring to which it is attached; thereby producingfused rings systems such as naphthyl, tetrahydronaphthyl, indenyl orindanyl.

It should be understood that the composition of the compounds of Formula1 can be mixtures with various values of p. For such mixtures the valuesof p can be described as number average degrees of oligomerization.

For the various embodiments, when m has a value other than zero, thecarbon bonded to Q

is preferably in the ortho and/or para position relative to the —OHgroup. It is appreciated that mixtures of compounds having the carbonbonded to the Q in both the ortho and the para position relative to the—OH group are possible. It is also possible to have the carbon bonded toQ

in the meta position relative to the —OH group.

In a third aspect, disclosed herein are methods of making compounds ofFormula 1, the methods comprising subjecting the trialdehyde of CDDT toconditions sufficient to convert the aldehyde groups to thediphenolmethyl groups.

In another aspect, the aldehydes of Formulas 2a and 2b may be reduced toform the corresponding trialcohol and dialcohol compounds. Methodsinclude using reducing agents, such as LiAlH₄, NaBH₄ or heterogeneouscatalysts (such as those based on Pd, Pt or Ni) and hydrogen gas,optionally in the presence of a solvent. Other methods are known in theart.

The trialdehydes disclosed herein may be in a mixture comprisingcyclododecane dialdehydes; thus, reduction of the mixture may result inthe formation of the tri and dialcohols.

In another aspect, the trialdehyde compounds of Formulas 2a and 2b maybe converted into the corresponding triamines. Methods include reductiveamination in the presence of ammonia or a primary amine with eitherhydrogen and a metal catalyst, or a reducing agent, such as NaCNBH₃ orNaBH₄ optionally in the presence of a solvent. Other methods are knownin the art. The trialdehydes disclosed herein may be in a mixturecomprising cyclododecane dialdehydes; thus, reductive amination of themixture will result in the formation of the triamine and the diamine.

Where each R group is independently CHO, CH₂OH, or CH₂NH₂, and thecyclododecane ring in Formula 2b is saturated or unsaturated.

Also disclosed are curable compositions that includes the compounds ofFormula 1 and a curing amount of a resin, such as an epoxy resin, and/ora catalytic amount of a catalyst and/or a cure accelerating amount of anaccelerating agent. The curable composition can also include a CDDTdiphenol, tetraphenol and/or an oligomer of the cyclododecanepolyphenol. For the various embodiments, the cyclododecane polyphenolsof Formula 1 can be used in forming a cured or a partially cured(B-staged) composition.

DETAILED DESCRIPTION OF THE INVENTION

As described above, in a first aspect, disclosed herein is a method ofhydroformylating cyclododecatriene to preferentially form thetrialdehyde.

In one embodiment, the method utilizes a rhodium compound. Variousrhodium compounds may be used, such as RhCl₃xH₂O, (RhCl(CO)₂)),Rh₆(CO)₁₆, Rh₄(CO)₁₂, (RhNO₃)₃, and Rh(CO)₂(AcAc), where x is the numberof water molecules associated with the RhCl₃. In one embodiment,Rh(CO)₂(AcAc) is preferred.

Organophosphites that may be used in the hydroformylation reactioninclude triphenylphosphite, tris(3-methyl-6-tert-butylphenyl) phosphite,tris(2,4-di-tert-butylphenyl) phosphite,di(2-tert-butylphenyl)-tert-butylphosphite, tri(C₁-C₆)alkyl phosphine orother suitable phosphorus-containing organics. In one embodiment,tris(2,4-di-tert-butylphenylphosphite is preferred.

Various solvents may be used when conducting the hydroformylationreaction. Preferred solvents are apolar and aprotic, such as C₅-C₁₀hydrocarbons, which include alkanes, cycloalkanes, and aromatics such asbenzene, toluene, and xylene. In one embodiment, hexanes and heptanesare particularly preferred with heptanes (either a mixture of isomers orpredominantly n-heptane) being most preferred.

The molar ratio of rhodium compound to organophosphite is from 10:1 to1:10. More preferably, the ratio is 5:1 to 1:9. Still more preferably,the organophosphite is used in excess. Ratios of 1:5 to 1:9 beingpreferred.

Once the rhodium compound, organophosphite ligand and the solvent arecombined, the activated catalyst complex is formed by adding a gascomprising CO and H₂. The ratio of the CO to H₂ in the gas is 100:1 to1:100. More preferably, the ratio is 50:1 to 1:50. Still morepreferably, the ratio is 10:1 to 1:10; even more preferred the ratio is1:1 (known as syn gas).

The reaction may be conducted in a high pressure reactor, such as a Paarreactor or a similar device.

Before beginning to heat the first reaction mixture, it is advisable,although not required, to purge the reaction vessel several times (suchas 3 times) with the CO and H₂ gas combination.

When heating the first mixture in the presence of a gas comprising COand H₂ to form a second mixture, the pressure in the reaction vessel is70 psig to 2200 psig. In further embodiments, it is 300 to 800 psig,with 400 to 700 psig more preferred and a pressure of 550 to 650 psigstill more preferred and a pressure of about 600 psig being mostpreferred. It is believed that higher pressures should facilitate thehydroformylation reaction.

The reaction may be stirred, agitated or otherwise mechanically mixed inorder to ensure mixing of the reaction components.

The first mixture is heated to temperatures of 50 to 120° C. (thereaction temperature is dependent on the solvent used and the pressurein the reaction container). More preferably the reaction is run at 70 to100° C.; still more preferably the reaction temperature is 75 to 85° C.;even more preferably, the reaction temperature is 80° C.

The hydroformylation reaction time is typically 4 to 24 hours. Morepreferably, it is 6 to 12 hours. Still more preferably, it is 8 to 10hours, with 9 hours being typical. In one aspect, the reaction is run at80° C. for 9 hours.

After the reaction is complete as determined using GC analysis or anyother method known to those skilled in the art, the reaction mixture isallowed to cool to room temperature. Then the cyclododecane trialdehyde(typically the lower layer, but this is solvent dependent) is separatedfrom the third mixture and optionally washed with a C₅-C₁₀ hydrocarbonthat is typically the same as the reaction solvent.

GC analysis of the resulting reaction product shows it contains greaterthan 90% trialdehyde, which is higher than any previously reportedyield.

The cyclododecatriene may be added to the second mixture or the secondmixture may be added to the cyclododecatriene. Adding thecyclododecatriene to the second mixture is preferred.

After removing the trialdehyde from the third mixture, the remainingrhodium catalyst, organophosphite and heptanes may be used to catalyzeanother hydroformylation of cyclododecatriene.

In an embodiment, the rhodium catalyst is Rh(CO)₂(AcAc), theorganophosphite is tris(2,4-di-tert-butylphenylphosphite, used inexcess, the solvent is heptanes, the first mixture is treated with a 1:1mixture of CO and H₂ at a pressure of 200 psig for a time sufficient toactivate the catalyst complex, and after adding the CDDT, the reactionis run at 80° C. for 9 hours.

The cyclododecane polyphenols of the present disclosure can be producedfrom cyclododecane aldehydes and/or ketones. For the variousembodiments, trialdehydes can be produced via hydroformylation of CDDTusing syngas, a phosphine ligand, and a transition metal (from Groups 3through 10) catalyst using a method such as described by G. Longoni, etal, J. of Molecular Catalysis 68, 7-21 (1991) or more generally inKirk-Othmer, ENCYCLOPEDIA OF CHEMICAL TECHNOLOGY, Fifth Edition, Vol.10, pp. 347-470 (2010). There are many variations in this process,including a method (U.S. Pat. No. 6,307,108 B1) that uses mixedpolar/nonpolar solvents to ease the problem of catalyst recycle andproduct separation. The resulting cyclododecane aldehydes can then becondensed with phenol to form the polyphenols.

Disclosed herein are cyclododecane polyphenols that are useful as curingagents for epoxy resins and/or as precursors to thermoset resins. Thepolyphenols of the present disclosure may provide high levelfunctionality (at least four functional groups/molecule with at leastsix functional groups per molecule being more preferred) when used in acurable composition. Surprisingly, however, the weight average molecularweights of these polyphenols may be relatively low. As a result, meltviscosities of curable compositions that include the polyphenolsdisclosed herein may be lower than those utilizing compounds havingcomparable or even lower level of functionality.

For the various embodiments, the polyphenols of the present disclosuremay be formed from the trialdehydes which may additionally containcyclododecanemonoaldehydes and/or dialdehydes. The use of trialdehydescontaining monoaldehydes and/or dialdehydes may allow for thepolyphenols of the present disclosure to achieve a high level offunctionality with a relatively low molecular weight, which may allowfor a relatively low melt viscosity of the curable composition.

When hydroformylating the CDDT to form the trialdehyde, minor amounts ofpartially or totally saturated CDDT monoaldehydes and/or dialdehydes mayalso be produced. Preferably, 30 weight percent or less (morepreferably, 15 weight percent or less, still more preferably, 10 weightpercent or less) of the reaction product is partially or totallysaturated monoaldehydes and/or dialdehydes. As a result, the trialdehydeis typically in a mixture having the same or similar product ratios asthe reaction product. In preferred mixtures, the trialdehyde is at least86 weight percent and the dialdehyde comprises less than 10 weightpercent of the product. More preferably, the trialdehyde is greater than90 (more preferably, greater than 91) weight percent and the dialdehydeis less than 9 (more preferably less than 8) weight percent of theproduct.

An example of these saturated dialdehydes with saturated cyclododecanering is represented by Formula 2b, wherein the R group is CHO.

The monoaldehydes and dialdehydes can be partially or totally separatedfrom the trialdehydes. For example, distillation or columnchromatography could be used.

In an additional embodiment, various weight percents of themonoaldehydes and/or dialdehydes with partially or totally saturatedcyclododecane ring could also be mixed with the trialdehydes. Usingmixtures containing the monoaldehydes and/or the dialdehydes may allowfor control of the level of functionality in the resulting curablecomposition. Thus, mixtures of CDDT diphenols and/or CDDT tetraphenolswith cyclododecane hexaphenols plus oligomers, if any, may be producedas an additional embodiment of the present disclosure. An example of theCDDT tetraphenols with saturated cyclododecane ring is represented bythe following Formula 3, where p=0 and m, R and Q are as describedherein.

Hydroformylation can also produce small amounts of isomeric ketones asdescribed by Longoni. These ketones can be the predominant products whenthe H₂/CO pressure is low (˜1 atm). If these ketones are present in theproduct mix they can be condensed with phenol to form polyphenols ofFormula 4, where p, m, and R are as described herein:

For the various embodiments, CDDT mono and diketones and cyclododecanetriketones useful in the present disclosure to prepare compositions ofFormula 1 where Q is an alkyl group can be produced through a multistepsynthesis, for example the chemistry given in Tetrahedron Letters, 28,769 (1987); Tetrahedron Letters, 27, 3033 (1986); Tetrahedron Letters,27, 933 (1986); Journal of the American Chemical Society, 107, 7179(1985); and Journal of the Chemical Society: Chemical Communications,1040 (1983).

Curable compositions formed with the polyphenols may also provide forcured compositions that have an enhanced glass transition temperature(Tg). Additionally, it is expected that the polyphenols will alsoprovide improvements in both moisture resistance and corrosionresistance, as well as enhanced electrical properties, of the curedcomposition, especially dissipation factor.

As mentioned above, in one aspect, the trialdehydes (or mixturescontaining said trialdehydes) are converted to polyphenol compounds ofFormula 1, which are useful as a monomer that may be used to makeoligomers or polymers. Examples of other monomers, oligomers or polymersthat may be made using this monomer include polyurethanes, polyethers,polyesters, epoxy resins, polycyanates, vinylbenzyl ethers,ethylenically unsaturated ethers such as allyl ethers and combinationsthereof. Certain of these compositions are also useful for making powdercoatings, electrical laminates and composites for aerospace.

As previously mentioned, the phenolic rings in Formula 1 may besubstituted. In one preferred embodiment, the phenolic rings areunsubstituted, where Q and p are as hereinbefore defined.

In another preferred embodiment, the phenolic rings are unsubstituted, Qis hydrogen, and p is as hereinbefore defined.

In another aspect, disclosed herein is a method of making compounds ofFormula 1 from the trialdehydes of cyclododecane.

While various methods are known for introducing the diphenolmethylgroup, including the use of protection and deprotection strategies, onepreferred method is as follows.

The trialdehydes are reacted with an optionally substituted phenol (asdescribed herein) in the presence of a catalyst. A solvent may be used,but preferably, the phenol is molten phenol.

The polyphenols are prepared via a condensation reaction of a mole ratioof the trialdehydes (and any dialdehydes and monoaldehydes) to phenoland/or substituted phenol, o-cresol, m-cresol, p-cresol,2,4-dimethylphenol; 2,6-dimethylphenol; 1-naphthol and 2-naphthol of1:20 to 1:6, and preferably from 1:15 to 1:8; in the presence of an acidcatalyst which is preferably from 0.1 to 2, and more preferably from 0.1to 1 wt. % based on the amount of phenol and/or substituted phenolcompound employed. Higher mole ratios than 1:20 of the phenol and/orsubstituted phenol may be employed, however doing so may requireadditional energy and thus expense to recover and recycle the excessphenol or substituted phenol.

Condensation reactions employing a large excess of the phenol and/orsubstituted phenol (and curing agents and/or curing catalysts) have beenfound to favor polyphenols having a low polydispersity and weightaverage molecular weight. Likewise, as the amount of the phenol and/orsubstituted phenol is reduced, there can be an increase in oligomers ofthe cyclododecane polyphenols, increasing the weight average molecularweight. Increased oligomer content favors higher hydroxyl level offunctionality per molecule which may be highly beneficial for certainend uses, for example, increasing the Tg, but at the cost of higherviscosity. Thus, while very large excesses of phenol and/or substitutedphenol may be used, the present disclosure in one embodiment employs themolar ratio provided above to produce products rich in hexaphenols, andlow in oligomers.

The condensation reaction to form the polyphenols of the presentdisclosure can also optionally include the use of a solvent. For theseembodiments, asolvent inert to the reaction and reaction products mayalso be employed, such as, for example, toluene or xylene. The solventmay additionally serve as an agent for the azeotropic removal of waterfrom the condensation reaction. With certain phenolic reactants withhigher melt viscosities, use of one or more solvents may be beneficialfor maintaining a suitable reaction medium.

Suitable acid catalysts include the protic acids, such as hydrochloricacid, sulfuric acid, phosphoric acid; metal oxides, such as zinc oxide,aluminum oxide, magnesium oxide; organic acids, such asp-toluenesulfonic acid, oxalic acid, 3-mercapto-1-propane sulfonic acidand combinations thereof. For the various embodiments,3-mercapto-1-propane sulfonic acid is a preferred acid catalyst orco-catalyst. If desired, the 3-mercapto-1-propane sulfonic acid may beattached to a solid support, as in U.S. Pat. No. 6,133,190.Surprisingly, it has been found that 3-mercapto-1-propane sulfonic acidis so highly active and selective in forming the polyphenols that thereis no need for an azeotropic removal of water from the reactionproducts. Rather, the water remains in the reactor, without quenchingthe phenolation reaction. Reaction temperatures and times vary, but canbe from 5 minutes to 48 hours and reaction temperatures of from 20° C.to 175° C. may be employed. Preferably reaction temperatures and timescan be from 15 minutes to 36 hours and reaction temperatures of from 30°C. to 125° C. Most preferably reaction temperatures and times can befrom 30 minutes to 24 hours and reaction temperatures of from 35° C. to75° C.

At the end of the reaction, the acidic catalyst can be removed byneutralization, for example, and/or by washing or extraction with water.Likewise, at the end of the reaction, excess phenol can be removed fromthe phenolated product, for example, by distillation or extraction.

For the various embodiments, the polyphenols of the present disclosurecan have a polydispersity index (PDI, which is known in the art as ameasure of distribution of molecular mass in a given polymer sample) ofless than 2. For example, the PDI of the polyphenols can be from 1.3 to1.4. These types of results indicate that the p values of each of thepolyphenols for the present disclosure are very uniform. This result issurprising, as phenolation reactions often times produce products havinga much larger polydispersity (e.g., from 2 to 5). Having a uniform chainlength for the polyphenols disclosed herein allow for more desirableviscosity predictability in the viscosity of the curable compositions.

The polydispersity values for certain of the cyclododecane polyphenolsare indicative of an increase in the level of functionality withoutsubstantial increase in Mw. High level of functionality and theresultant high crosslink density can provide very desirable high Tg.

For the various embodiments, starting with the trialdehydes allows for ahigh (i.e., greater than 2, more preferably greater than 3, still morepreferably greater than 4, even more preferably 5 or more functionalgroups per molecule) level of functionality to be achieved in theresulting polyphenols without a large increase in the compound's Mw.This is not the case with previous attempts to form polyphenols withhigh levels of functionality. For example, embodiments of the presentdisclosure provide for functionalities of 6 hydroxyl groups withequivalent weights as low as 128 grams per hydroxyl equivalent.Embodiments described herein also allow for a scalable progression inthe level of functionality to be achieved without significant increasesin the molecular weight and viscosity of the curable composition.

The catalyst may be added in one portion, portionwise or continuously.If added portionwise, the portions may be of the same size, but need notbe so. Catalyst portions may be added so as to control one or moreparameters of the reaction such as reaction temperature.

After the reaction is completed, the unreacted phenol, which istypically used in excess, is removed using methods known in the art,such as by heating and applying a vacuum. The resulting solid productmay be washed with water repeatedly until the phenol content no longerdecreases, as determined by HPLC, GC or other type of analysis as knownin the art. If desired, the resulting solid may be dried in a vacuumoven or using other means known in the art.

The product may be further purified using methods such as preparativeHPLC or column chromatography, or it may be used as is.

As noted above, the compounds of Formula 1 may be used to make a powdercoating composition. Methods known in the art may be used. For example,the components of the powder coating composition described herein aretypically pre-blended or ground in a grinder, and the resulting mixtureexiting from the grinder is then fed into an extruder.

In the extruder, the powder mixture is heated at low temperature andmelted into a semi-liquid form. During this process, the components ofthe molten mixture are thoroughly and uniformly dispersed. Because ofthe fast operation of the extruder and the relatively low temperaturewithin the extruder, the components of the powder coating compositionsdescribed herein will not undergo a significant chemical reaction. Theresulting molten extrudate of the powder coating compositions describedherein exit from the extruder and are then passed from the extruder ontoa flaker, which then feeds the flakes of the composition into amill/classifier to obtain a powder coating final product with a desiredparticle size. The final powder coating product is then packaged inclosed containers, using a packaging unit to avoid moisture ingressioninto the product. The apparatus for manufacturing the powder coatingcomposition described herein, such as the pre-blending station orgrinder; the extruder, the flaker, the mill/classifier, and thepackaging unit are all well known equipment in the art. The powdercoating compositions described herein may be applied to a substrate byvarious methods. For example, in one embodiment, the powder coatingcomposition may be applied to a substrate by (1) heating the substrateto a suitable curing temperature for the composition and (2) applyingthe powder coating composition by known means such as an electrostaticspray or a fluidized bed. In another embodiment, the powder coatingcomposition may be applied to a cold substrate by (1) applying thepowder coating composition to the substrate (e.g. with an electrostaticapplication method); and (2) heating the powder and the substrate to atemperature at which the powder flows and cures.

In some embodiments, powder coatings may be formed by applying athermosettable resin composition to a substrate and then curing thecurable thermosettable resin composition.

Curing of the thermosettable resin compositions disclosed herein usuallyrequires a temperature of at least 30° C., up to 250° C., for periods ofminutes up to hours, depending on the thermosettable resin used, thecuring agent used, and the catalyst, if used. In other embodiments,curing may occur at a temperature of at least 100° C., for periods ofminutes up to hours. Post-treatments may be used as well, suchpost-treatments ordinarily being at temperatures between 100° C. and200° C.

For example, the curing reaction of the thermosettable composition maybe conducted at a temperature, generally, between 20° C. and 250° C.,preferably between 50° C. and 200° C., more preferably between 50° C.and 150° C. The time of curing the thermosettable resin composition maybe for a predetermined period of time which can range from minutes up tohours, generally the reaction time is more than 1 minute and less than24 hours, preferably between 5 minutes and 6 hours, and more preferablybetween 10 minutes and 2 hours. The curing conditions of thethermosettable resin can also depend on the components used, and anyoptional components added to the composition such as a catalyst, ifused. In other embodiments, partial curing may occur at a firsttemperature followed by a second temperature or post-treatment, suchpost-treatments ordinarily being at temperatures above 100° C.,preferably between 100° C. and 200° C.

Thermoset resins may be formed by curing the curable thermosettableresin compositions described herein. The resulting thermoset resins maycomprise a thermoset or a thermoset network structure with fillersand/or other additives. The term “thermoset” or “thermoset networkstructure” used herein refers to a substantially cured and crosslinkedthermoset resin structure.

The resulting powder coatings display excellent thermo-mechanicalproperties, such as good toughness and mechanical strength, whilemaintaining high thermal stability.

Curable resin compositions may comprise compounds of Formula 1 and atleast one curing agent. Optionally, one or more catalysts and/or otheradditives may also be included. In one embodiment, the curing agent isan epoxy resin having an average of more than one epoxide group permolecule. The epoxide group can be attached to an oxygen, a sulfur or anitrogen atom or the single bonded oxygen atom attached to the carbonatom of a —CO—O— group. The oxygen, sulfur, nitrogen atom, or the carbonatom of the —CO—O— group may be attached to an aliphatic,cycloaliphatic, polycycloaliphatic or aromatic hydrocarbon group. Thealiphatic, cycloaliphatic, polycycloaliphatic or aromatic hydrocarbongroup can be substituted with an inert substituents including, but notlimited to, halogen atoms, preferably fluorine, bromine or chlorine;nitro groups; or the groups can be attached to the terminal carbon atomsof a compound containing an average of more than one—(O—CHR^(a)—CHR^(a))_(t)— group, where each R^(a) is independently ahydrogen atom, an alkyl, or a haloalkyl group containing from one to twocarbon atoms, with the proviso that only one R^(a) group can be ahaloalkyl group, and t has a value from one to about 100, preferablyfrom one to about 20, more preferably from one to about 10, and mostpreferably from one to about 5.

More specific examples of the epoxy resin which can be used includediglycidyl ethers of 1,2-dihydroxybenzene (catechol);1,3-dihydroxybenzene (resorcinol); 1,4-dihydroxybenzene (hydroquinone);4,4′-isopropylidenediphenol (bisphenol A);4,4′-dihydroxydiphenylmethane; 3,3′,5,5′-tetrabromobisphenol A;4,4′-thiodiphenol; 4,4′-sulfonyldiphenol; 2,2′-sulfonyldiphenol;4,4′-dihydroxydiphenyl oxide; 4,4′-dihydroxybenzophenone;1,1′-bis(4-hydroxyphenyl)-1-phenylethane; 3,3′-5,5′-tetrachlorobisphenolA; 3,3′-dimethoxybisphenol A; 4,4′-dihydroxybiphenyl;4,4′-dihydroxy-alpha-methylstilbene; 4,4′-dihydroxybenzanilide;4,4′-dihydroxystilbene; 4,4′-dihydroxy-alpha-cyanostilbene;N,N′-bis(4-hydroxyphenyl)terephthalamide; 4,4′-dihydroxyazobenzene;4,4′-dihydroxy-2,2′-dimethylazoxybenzene;4,4′-dihydroxydiphenylacetylene; 4,4′-dihydroxychalcone;4-hydroxyphenyl-4-hydroxybenzoate; dipropylene glycol; poly(propyleneglycol); thiodiglycol; the triglycidyl ether oftris(hydroxyphenyl)methane; the polyglycidyl ethers of a phenol or alkylor halogen substituted phenol-aldehyde acid catalyzed condensationproduct (novolac resins); the tetraglycidyl amines of4,4′-diaminodiphenylmethane; 4,4′-diaminostilbene;N,N′-dimethyl-4,4′-diaminostilbene; 4,4′-diaminobenzanilide;4,4′-diaminobiphenyl; the polyglycidyl ether of the condensation productof a dicyclopentadiene or an oligomer thereof and a phenol or alkyl orhalogen substituted phenol; and combinations thereof.

The epoxy resin which can be used may also include an advanced epoxyresin. The advanced epoxy resin may be a product of an advancementreaction of an epoxy resin with an aromatic di- and polyhydroxyl, orcarboxylic acid containing compound. The epoxy resin used in theadvancement reaction may include one or more of the aforesaid epoxyresins.

Preparation of the aforementioned advanced epoxy resin products can beperformed using known methods, for example, an advancement reaction ofan epoxy resin with one or more suitable compounds having an average ofmore than one reactive hydrogen atom per molecule, where the reactivehydrogen atom is reactive with an epoxide group in the epoxy resin. Theratio of the compound having an average of more than one reactivehydrogen atom per molecule to the epoxy resin is generally from about0.01:1 to about 0.95:1, preferably from about 0.05:1 to about 0.8:1, andmore preferably from about 0.10:1 to about 0.5:1 equivalents of thereactive hydrogen atom per equivalent of the epoxide group in the epoxyresin.

In addition to the aforementioned dihydroxyaromatic and dicarboxylicacid compounds, examples of the compound having an average of more thanone reactive hydrogen atom per molecule may also include dithiol,disulfonamide or compounds containing one primary amine or amide group,two secondary amine groups, one secondary amine group and one phenolichydroxy group, one secondary amine group and one carboxylic acid group,or one phenolic hydroxy group and one carboxylic acid group, andcombinations thereof.

The advancement reaction may be conducted in the presence or absence ofa solvent with the application of heat and mixing. The advancementreaction may be conducted at atmospheric, superatmospheric orsubatmospheric pressures and at temperatures of from about 20° C. toabout 260° C., preferably, from about 80° C. to about 240° C., and morepreferably from about 100° C. to about 200° C.

The time required to complete the advancement reaction depends upon thefactors such as the temperature employed, the chemical structure of thecompound having more than one reactive hydrogen atom per moleculeemployed, and the chemical structure of the epoxy resin employed. Highertemperature may require shorter reaction time whereas lower temperaturerequires a longer period of reaction time. In general, the time forcompletion of the advancement reaction may range from about 5 minutes toabout 24 hours, preferably from about 30 minutes to about 8 hours, andmore preferably from about 30 minutes to about 4 hours.

A catalyst may also be added in the advancement reaction. Examples ofthe catalyst may include phosphines, quaternary ammonium compounds,phosphonium compounds and tertiary amines. The catalyst may be employedin quantities of from about 0.01 percent to about 3 percent, preferablyfrom about 0.03 percent to about 1.5 percent, and more preferably fromabout 0.05 percent to about 1.5 percent by weight based upon the totalweight of the epoxy resin.

Other details concerning an advancement reaction useful in preparing theadvanced epoxy resin are provided in U.S. Pat. No. 5,736,620 and in theHandbook of Epoxy Resins by Henry Lee and Kris Neville.

Examples of the curing agents and/or catalysts useful for the curablecomposition include aliphatic, cycloaliphatic, polycycloaliphatic oraromatic primary monoamines, aliphatic, cycloaliphatic,polycycloaliphatic or aromatic primary and secondary polyamines,carboxylic acids and anhydrides thereof, aromatic hydroxyl containingcompounds, imidazoles, guanidines, urea-aldehyde resins,melamine-aldehyde resins, alkoxylated urea-aldehyde resins, alkoxylatedmelamine-aldehyde resins, amidoamines, epoxy resin adducts, andcombinations thereof.

Particularly preferred examples of the curing agent includemethylenedianiline; 4,4′-diaminostilbene;4,4′-diamino-alpha-methylstilbene; 4,4′-diaminobenzanilide;dicyandiamide; ethylenediamine; diethylenetriamine;triethylenetetramine; tetraethylenepentamine; urea-formaldehyde resins;melamine-formaldehyde resins; methylolated urea-formaldehyde resins;methylolated melamine-formaldehyde resins; bisphenols such as bisphenolA; bisphenol F (bis-4-hydroxyphenyl methane); bisphenol S(bis-4-hydroxyphenyl sulfone); TBBA (tetrabromobisphenol A);phenol-formaldehyde novolac resins; cresol-formaldehyde novolac resins;sulfanilamide; diaminodiphenylsulfone; diethyltoluenediamine;t-butyltoluenediamine; bis-4-aminocyclohexylamine; isophoronediamine;diaminocyclohexane; hexamethylenediamine, piperazine;1-(2-aminoethyl)piperazine; 2,5-dimethyl-2,5-hexanediamine;1,12-dodecanediamine; tris-3-aminopropylamine; and combinations thereof.

Particularly preferred examples of the curing catalyst include borontrifluoride, boron trifluoride etherate, aluminum chloride, ferricchloride, zinc chloride, silicon tetrachloride, stannic chloride,titanium tetrachloride, antimony trichloride, boron trifluoridemonoethanolamine complex, boron trifluoride triethanolamine complex,boron trifluoride piperidine complex, pyridine-borane complex,diethanolamine borate, zinc fluoroborate, metallic acylates such asstannous octoate or zinc octoate and combinations thereof.

For the various embodiments, the curing catalyst may be employed in anamount that will effectively cure the curable composition. The amount ofthe curing catalyst may also depend upon the polyphenol, epoxy resin,and curing agent, if any, employed in the curable composition.

Generally, the curing catalyst may be used in an amount of from about0.001 to about 2 percent by weight of the total curable composition. Inaddition, one or more of the curing catalysts may be employed toaccelerate or otherwise modify the curing process of the curablecomposition.

The curing agent may be employed in conjunction with the polyphenol tocure the curable composition. The amounts of combined curing agent andpolyphenol are from about 0.60:1 to about 1.50:1, and preferably fromabout 0.95:1 to about 1.05:1 equivalents of reactive hydrogen atomcollectively in the curing agent and the polyphenol.

AcAc or acac is understood to mean the bidentate acetylacetonate ligand.

As used herein, “cyclododecane trialdehyde” and “trialdehyde” and“trialdehydes” refer to a mixture of the trialdehydes of cyclododecane,which includes all possible isomers, including, for example, the 1,4,8isomer; 1,4,9 isomer; the 1,5,8 isomer; and the 1,5,9 isomers. Allenantiomers and diastereomers are also encompassed by this definition.

1,5,9 trans, trans, cis CDDT is the most common CDDT isomer.

EEW means epoxide equivalent weight, and Tg means glass transitiontemperature.

EXAMPLES Example 1 Hydroformylation of cyclododecatriene at 80° C. and600 psig with Catalyst Recycle

A 100 mL Hastelloy C Parr reactor was cleaned, dried, and pressuretested with nitrogen at the reaction pressure. In a glove box wasprepared a solution of Rh(CO)₂(AcAc) (50.5 mg), tris(2,4-di-tertbutylphenyl)phosphite (0.660 g), and heptane (15.1 g). Thecatalyst/ligand solution drawn into a 25 mL gas-tight syringe and thesolution was transferred into the Parr reactor. The reactor was purgedwith syn gas (CO/H₂ 50:50, 200 psig) three times. The catalyst mixturewas stirred at 600 rpm with 200 psig syn gas at 80-90° C. for 30 minutesto activate the catalyst complex, and then cooled to 25° C. overnightunder 200 psig syn gas pressure. The reactor was warmed to 45° C., thesyn gas was vented, and cyclododecatriene (34.3 g) was added with a 100mL gas-tight syringe. The mixture was purged with syn gas thenpressurized to 150 psig syn gas. The reaction was heated to 80° C. Whenthe temperature reached 79° C., the syn gas pressure was increased to600 psig. Samples were removed periodically via a three-way valve andanalyzed by GC. The reaction was stopped after 9 hours by cooling toroom temperature overnight under 200 psig syn gas and no agitation. Theclear lower product phase was collected from the reactor via thesampling line (38.4 g). The catalyst solution was left in the reactorunder 130 psig syn gas and room temperature. The syn gas was vented.Additional cyclododecatriene (34.3 g) was added to the reactor via agas-tight syringe. The reactor was purged with syn gas and pressured to600 psig syn gas. The reactor was heated to 80° C. for 6 hours andcooled to room temperature overnight. The next day, the reaction wascontinued at 80° C. for 3.5 hours. The reaction was cooled to roomtemperature overnight under 150 psig syn gas and no agitation. Theproduct (49.4 g) was collected through the sample line. The remainingreactor contents of product and catalyst solution were collected and thereactor was cleaned with THF and dried.

Several trialdehyde reaction products were combined and analyzed usingGC and NMR. GC analysis of the combined products showed the crudealdehyde contained the mono, bis, and trialdehydes in the followingapproximate ratio: 1:8:93. A Bruker instrument was used to collect NMRdata at 300.13 MHz for proton and 75.47 MHz for carbon. CDCl₃ was usedas the solvent with TMS internal standard. A 10 second delay (D1) wasused in proton experiments used for quantization of aldehyde and olefin.

Internal Standard GC Method for Cyclododecatriene Hydroformylation(Agilent 6850)

-   Column: J&W DB-1 30 m×0.32 mm I.D.×1.0 μm film thickness capillary    column.-   Oven: Initial temp: 100° C. (2 min hold), 15° C./min to 300° C.    (9.67 min hold).-   Run time: 25 minutes; Sample: 200-250 mg sample and 100 mg triglyme    (internal standard) in 5 mL toluene; Inlet mode, temp and split    ratio: split, 280° C., and 100:1, respectively. Detector (FID)    Temperature was 300° C.; Injection volume was 1 uL.

Example 2 Preparation of Polyphenol of Cyclododecane Trialdehyde

Cyclododecane trialdehyde obtained from the hydroformylation ofcyclododecatriene was analyzed by gas chromatography demonstrating thefollowing composition: cyclododecatriene (0.15 wt. %), cyclododecanemonoaldehyde (0.16 wt. %), cyclododecane dialdehyde (9.52 wt. %) andcyclododecane trialdehyde (88.72 wt. %). Cyclododecane trialdehyde(39.74 g, 0.16 mole, 0.48 aldehyde eq) and molten phenol (301.2 g, 3.2moles) were added to a 2 L glass three neck round bottom reactor. Thereactor was additionally outfitted with an ambient temperature (22° C.)condenser and a thermometer, both affixed to the reactor via a Claisenadaptor, plus an overhead nitrogen inlet, a glass stirring shaft with aTeflon™ (Teflon™ fluorocarbon resin is a trademark of E.I. duPont deNemours) stirrer blade which was coupled to a variable speed motor toprovide mechanical stirring and a thermostatically controlled heatingmantle and fan which alternately cooled the reactor exterior.

Overhead nitrogen flow (1 L per min) commenced, followed by heating andstirring. Once the temperature reached 65° C., forming a light ambercolored solution, addition of four approximately equal aliquots of3-mercapto-1-propane sulfonic acid catalyst (total catalyst used was1.25 g, 0.05 mole % with respect to cyclododecane trialdehyde reactant)commenced into the stirred solution. The initial aliquot of catalystimmediately turned the solution light yellow then back to a darker ambercolor. The remaining three aliquots of catalyst were added over the next16 min with maintenance of the 65° C. reaction temperature. The solutionin the reactor became dark violet colored 39 min after addition of thefinal aliquot of catalyst. The reaction temperature was maintained at65° C. for the next 16.3 hr.

At the end of the reaction time, the reactor contents were added to a 1L single neck round bottom flask and rotary evaporated using a maximumoil bath temperature of 100° C. to remove the bulk of the unreactedphenol. The solid product recovered from the rotary evaporation wasadded to a 2 L glass beaker and magnetically stirred with 1 L of boilingDI water followed by filtration over a medium fritted glass funnel torecover the washed solid. Washing of the recovered solid with boiling DIwater was repeated followed by HPLC analysis of a sample of the washedproduct which demonstrated the presence of 2.37 area % residual phenol.An additional washing with DI water did not provide any further decreasein phenol content. The solids were added to a ceramic dish and dried inthe vacuum oven at 100° C. for 16 hr, removed, ground to a fine powder(109.41 g) and dried in the vacuum oven for an additional 16 hr toprovide the polyphenol of cyclododecane trialdehyde as a reddish tancolored powder (107.00 g). HPLC analysis of a sample of the productdemonstrated the presence of 1.89 area % residual phenol. FTIRspectrophotometric analysis of a KBr pellet revealed completedisappearance of the aldehyde carbonyl stretch at 1721.9 cm⁻¹ withappearance of strong aromatic ring absorbance at 1610.8 (shoulder at1595.5) and 1510.2 cm⁻¹, broad strong hydroxyl O—H stretching centeredat 3382.3 cm⁻¹, and broad strong C—O stretching at 1229.4 (shoulder at1170.5) cm⁻¹. HPLC analysis revealed the polyphenol of cyclododecanetrialdehyde included multiple components eluting between 3.24 to 8.30min (phenol residual eluted at 2.49 min).

For all HPLC analyses, a Hewlett Packard 1090 Liquid Chromatograph wasemployed using a Zorbax Eclipse® (Agilent) XDB-C8 analytical column (5μ,4.6×150 mm) with an Eclipse® (Agilent) XDB-C8 analytical guard column(5μ, 4.6×12.5 mm). The columns were maintained in the chromatograph ovenat 40° C. Acetonitrile and water (treated with 0.05% aqueouso-phosphoric acid) were used as the eluents and were initially deliveredvia the pump at a rate of 1.000 mL per min as a 50/50% solution,respectively, changing after 5 min to a 90/10% solution and held thereinfor the next 15 min. The acetonitrile used was HPLC grade, 100.0% purity(by gas chromatography), with a UV cutoff of 189 nm. The o-phosphoricacid used was nominally 85% pure (actual assay 85.1%). The water usedwas HPLC grade. A diode array detector employed for the sample analysiswas set at 225 nm and the reference was set at 550 nm.

Example 3 Preparation of a Curable Powder Composition and Curing of anEpoxy Resin with Polyphenol of Cyclododecane Trialdehyde

Diglycidyl ether of bisphenol A [D.E.R.™ 330, Trademark of The DowChemical Company (“Dow”) or an affiliated company of Dow] (5.0696 g,0.02836 epoxide eq) was added to a 100 mL glass beaker additionallycontaining a magnetic stir bar. The diglycidyl ether had an EEW of178.75. All weighing was completed on scales with 4 place accuracy.Heating and stirring of the diglycidyl ether to 150-160° C. commencedfollowed by the addition of polyphenol of cyclododecatriene trialdehyde(3.6338 g, 0.02836 hydroxyl eq) from Example 2 in eight approximatelyequal aliquots. Each aliquot was allowed to dissolve before the additionof the next aliquot. The resultant amber colored solution was cooled to23° C. to provide a solid which could be ground to a powder product.

A portion (4.0074 g) of the powder blend of the diglycidyl ether andpolyphenol of cyclododecatriene trialdehyde was added to an aluminumdish and placed in an oven preheated to 120° C. A solution of2-methylimidazole (0.2006 g) in cyclohexanone (2.0160 g) was preparedand warmed to maintain the solution state. A single drop (0.0165 g) ofthe 2-methylimidazole solution was added to the molten blend ofdiglycidyl ether and polyphenol of cyclododecatriene trialdehydefollowed by vigorous stirring, providing 0.41 mg of 2-methylimidazoleper g of blend. Approximately 0.1 g of the 2-methylimidazole catalyzedblend was immediately removed and cooled to 23° C. to provide a samplefor DSC analysis. The remaining blend was cured by placing the aluminumdish in an oven which had been preheated to 200° C. for 2 hr.

For analysis of curing, a DSC 2910 Modulated DSC (TA Instruments) wasemployed, using a heating rate of 7° C. per min from 0° C. to 350° C.under a stream of nitrogen flowing at 35 cubic centimeters per min, withholding at 0° C. for 2 min. For a portion (9.6 mg) of the2-methylimidazole catalyzed blend, a 217.7° C. onset to cure wasdetected, followed by a cure exotherm having a maximum of 300.9° C. andan enthalpy of 192.2 J/g, and an end of cure of 315.6° C.

DSC analysis of a portion (27.0 mg) of the product cured at 200° C. wascompleted using a heating rate of 7° C. per min from 0° C. to 325° C.under a stream of nitrogen flowing at 35 cubic centimeters per min, withholding at 325° C. for 5 min. The first scanning detected an exothermwith a 205.2° C. onset, an exotherm with a maximum of 290.7° C. and anenthalpy of 66.5 J/g, and an end of 312.7° C. This exotherm wasattributed to additional curing. Second, third and fourth scannings werefeatureless, with no Tg detected up to the 325° C. maximum temperaturefor the DSC analysis.

Example 4 Repeat of Preparation of a Curable Powder Composition andCuring of an Epoxy Resin with Polyphenol of Cyclododecane Trialdehyde

Example 3 was repeated using diglycidyl ether of bisphenol A (5.4939 g,0.03074 epoxide eq) and polyphenol of cyclododecatriene trialdehyde(3.9379 g, 0.03074 hydroxyl eq) from Example 1. A portion (4.0010 g) ofthe powder blend of the diglycidyl ether and polyphenol ofcyclododecatriene trialdehyde was catalyzed with 2-methylimidazolesolution (0.0210 g) using the method of Example 3, providing 0.52 mg of2-methylimidazole per g of blend. Approximately 0.1 g of the2-methylimidazole catalyzed blend was immediately removed and cooled to23° C. to provide a sample for DSC analysis. The remaining blend wascured by placing the aluminum dish in an oven which had been preheatedto 200° C. for 2 hr.

DSC analysis of curing was repeated using the method of Example 3. For aportion (11.2 mg) of the 2-methylimidazole catalyzed blend, a 212.7° C.onset to cure was detected, followed by a cure exotherm having a maximumof 298.0° C. and an enthalpy of 240.7 J/g, and an end of cure of 311.8°C.

DSC analysis of a portion (25.6 mg) of the product cured at 200° C. wascompleted using the method of Example 3. The first scanning detected anexotherm with a 196.53° C. onset, an exotherm with a maximum of 293.2°C. and an enthalpy of 94.5 J/g, and an end of 312.2° C. This exothermwas attributed to additional curing. Second, third and fourth scanningswere featureless, with no Tg detected up to the 325° C. maximumtemperature for the DSC analysis.

Comparative Example A Preparation of a Curable Composition and Curing ofan Epoxy Resin with a Phenolic Curing Agent

Comparative Example A was completed using diglycidyl ether of bisphenolA [D.E.R.™ 330] (5.4939 g, 0.03074 epoxide eq) and D.E.H.™ 85 (7.4338 g,0.02859 hydroxyl eq) and the method of Example 3. D.E.H.™ 85 is aphenolic curing agent based on an unmodified solid reaction product ofliquid epoxy resin and bisphenol A available from The Dow ChemicalCompany or an affiliate thereof. The resultant yellow colored solutionwas cooled to 23° C. to provide a solid which could be flaked butsintered on standing.

A portion (4.0002 g) of the blend of the diglycidyl ether and D.E.H.™ 85was catalyzed with 2-methylimidazole solution (0.0206 g) using themethod of Example 2, providing 0.51 mg of 2-methylimidazole per g ofblend. Approximately 0.1 g of the 2-methylimidazole catalyzed blend wasimmediately removed and cooled to 23° C. to provide a sample for DSCanalysis. The remaining blend was cured by placing the aluminum dish inan oven which had been preheated to 200° C. for 2 hr.

DSC analysis of curing was repeated using the method of Example 3. For aportion (10.4 mg) of the 2-methylimidazole catalyzed blend, a 94.9° C.onset to cure was detected, followed by a cure exotherm having a maximumof 177.0° C. and an enthalpy of 107.2 J/g, and an end of cure of 221.8°C.

DSC analysis of a portion (33.3 mg) of the product cured at 200° C. wascompleted using the method of Example 3. The first scanning detected aTg of 101.9° C. Second, third and fourth scannings detected a Tg of100.5° C., 99.8° C., and 99.8° C., respectively.

Example 5 Preparation of a Curable Powder Composition and Curing of anEpoxy Resin with Polyphenol of Cyclododecane Trialdehyde Using Increased2-Methylimidazole Catalyst

A. Use of 1.25 mg of 2-Methylimidazole per g of Blend of Epoxy Resinwith Polyphenol of Cyclododecane Trialdehyde

Example 3 was repeated using diglycidyl ether of bisphenol A (4.4911 g,0.02513 epoxide eq) and polyphenol of cyclododecatriene trialdehyde(3.2191 g, 0.02513 hydroxyl eq) from Example 2 in eight approximatelyequal aliquots. A portion (2.5839 g) of the blend of the diglycidylether and polyphenol of cyclododecatriene trialdehyde was catalyzed with2-methylimidazole solution prepared by dissolving 2-methylimidazole(0.0032 g) in cyclohexanone (0.032 g) providing 1.25 mg of2-methylimidazole per g of blend. Approximately 0.1 g of the2-methylimidazole catalyzed blend was immediately removed and cooled to23° C. to provide a sample for DSC analysis.

DSC analysis of curing was repeated using the method of Example 3. For aportion (11.9 mg) of the 2-methylimidazole catalyzed blend, a 90.0° C.onset to cure was detected, followed by a cure exotherm having a maximumof 169.3° C. and an enthalpy of 52.0 J/g, and an end of cure of 201.9°C. A second cure exotherm was detected with a 207.7° C. onset to cure,followed by a cure exotherm having a maximum of 304.0° C. and anenthalpy of 120.4 J/g, and an end of cure of 323.0° C. A second scanningwas featureless, with no Tg detected up to the 325° C. maximumtemperature for the DSC analysis.

B. Use of 2.5 mg of 2-Methylimidazole per g of Blend of Epoxy Resin withPolyphenol of Cyclododecane Trialdehyde

A portion (2.1841 g) of the blend of the diglycidyl ether and polyphenolof cyclododecatriene trialdehyde from A. above was catalyzed with2-methylimidazole solution prepared by dissolving 2-methylimidazole(0.0055 g) in cyclohexanone (0.055 g) providing 2.5 mg of2-methylimidazole per g of blend. Approximately 0.1 g of the2-methylimidazole catalyzed blend was immediately removed and cooled to23° C. to provide a sample for DSC analysis.

DSC analysis of curing was repeated using the method of Example 3. For aportion (9.3 mg) of the 2-methylimidazole catalyzed blend, a 86.6° C.onset to cure was detected, followed by a cure exotherm having a maximumof 190.4° C. and an enthalpy of 58.8 J/g, and an end of cure of 233.0°C. A gradual exothermic shift in the baseline was detected with a 252.9°C. onset. A second scanning was featureless, with no Tg detected up tothe 325° C. maximum temperature for the DSC analysis.

Example 6 Preparation of a Curable Powder Composition and Curing of anEpoxy Resin with Polyphenol of Cyclododecane Trialdehyde and PhenolicCuring Agent Mixture

Example 3 was repeated using diglycidyl ether of bisphenol A (5.4456 g,0.03047 epoxide eq), polyphenol of cyclododecatriene trialdehyde (0.9785g, 0.007616 hydroxyl eq) from Example 2 and D.E.H.™ 85 (5.9407 g,0.022849 hydroxyl eq) from Comparative Example A. A portion (4.0345 g)of the powder blend of the diglycidyl ether, polyphenol ofcyclododecatriene trialdehyde and D.E.H.™ 85 was catalyzed with2-methylimidazole solution (0.0219 g) using the method of Example 3,providing 0.54 mg of 2-methylimidazole per g of blend. Approximately 0.1g of the 2-methylimidazole catalyzed blend was immediately removed andcooled to 23° C. to provide a sample for DSC analysis. The remainingblend was cured by placing the aluminum dish in an oven which had beenpreheated to 200° C. for 2 hr.

DSC analysis of curing was repeated using the method of Example 3. For aportion (12.6 mg) of the 2-methylimidazole catalyzed blend, a 91.6° C.onset to cure was detected, followed by a cure exotherm having a maximumof 178.7° C. and an enthalpy of 158.8 J/g, and an end of cure of 223.9°C.

DSC analysis of a portion (34.3 mg) of the product cured at 200° C. wascompleted using the method of Example 3. First, second, third and fourthscannings revealed Tg's of 104.7° C., 108.9° C., 108.6° C., and 108.1°C., respectively.

What is claimed is:
 1. A method of hydroformylating cyclododecatriene to form a trialdehyde, the method comprising: a) preparing a first mixture comprising a rhodium compound and an organophosphite ligand in a solvent; b) heating the first mixture in the presence of a gas comprising CO and H₂ to form a second mixture comprising an activated catalyst complex; and c) combining cyclododecatriene and the second mixture to form a third mixture.
 2. A method according to claim 1, wherein the rhodium compound is RhCl₃xH₂O, (RhCl(CO)₂)), Rh₆(CO)₁₆, Rh₄(CO)₁₂, (RhNO₃)₃, or Rh(CO)₂(AcAc), where x represents the number of water molecules associated with the RhCl₃.
 3. A method according to claim 1, wherein the organophosphite is triphenylphosphite, tris(3-methyl-6-tert-butylphenyl) phosphite, tris(2,4-di-tert-butylphenyl) phosphite, di(2-tert-butylphenyl)-tert-butylphosphite, or tri(C₁-C₆)alkyl phosphine.
 4. A method according to claim 1, wherein the solvent is a C₅-C₁₀ hydrocarbon.
 5. A method according to claim 1, wherein the third mixture is heated at 70 to 100° C. for 6 to 12 hours.
 6. A method according to claim 1, wherein the ratio of the rhodium compound to the organophosphite ligand is from 10:1 to 1:10.
 7. A method according claim 1, wherein the heating the first mixture in the presence of a gas comprising CO and H₂ to form a second mixture is conducted at a pressure of 70 psig to 2200 psig.
 8. A method according to claim 1, wherein the rhodium compound is Rh(CO)₂(AcAc), the organophosphite ligand is tris(2,4-di-tert-butylphenylphosphite), the solvent is heptanes, the first mixture is treated with a 1:1 mixture of CO and H₂ at a pressure of 200 psig for a time sufficient to activate the catalyst complex, and after adding the cyclododecatriene the reaction is run at 80° C. for 9 hours. 